HEAD INJURIES Flashcards
TBI contributes significantly to the death of approximately ______ of all trauma victims.
half
The brain is surrounded by how much csf?
150ml
Brain tissue, blood, and CSF exert a pressure within the brain, which isreferred to as
intracranial pressure (ICP)
Hemorrhage or edema that leads to herniation of the brain will compress what CN, Leading to pupillary dilation?
Cranial nerve III (oculomotor)
What pressure is used to characterize pressure driving blood into the brain
Mean arterial pressure (MAP)
How do you calc MAP?
(systole +diastole x2/3) or diastole + 1/3 pulse pressure
What is the amount of pressure it takes to push blood through cerebral circulation. To maintain oxygen, glucose delivery
Cerebral perfusion pressure (CPP)
CPP is calculated how?
MAP-ICP
Normal CPP =
70-80mmhg
Historically _____ has been use to lower ICP
hyperventilation
What type of injury?
(a)Direct trauma to the brain
(b)Contusion, hemorrhages, lacerations or direct mechanical injury
(c) Neural tissue does not regenerate well therefore low expectation of recovery of the tissue associated
Primary brain injury
Types of secondary injury include:
1) Mass effect – elevated ICP (can lead to herniation)
2) Hypoxia (inadequate delivery of O2)
3) Hypotension
2 biggest predictors of poor outcome in head trauma are
-Amount of time spent with ICP > 20mmHg
-Time spent with systolic BP < 90mmHg
Cushing’s triad refers to
elevated systolic BP, bradycardia and
abnormal respirations (Cheyne-stokes)
Once life threatening injuries have been managed if time permits or during transport perform _____
secondary assessment
single most important observation for TBI during secondary survey
Constant/continuous observation of mental status
Depressed vs non depressed skull fractures.
______ can often be palpated and may require surgical intervention
Depressed
________ - suspect if CSF drainage or delayed (several hours) findings of periorbital ecchymosis or battle signs are seen
Basilar skull fracture